1. Field of the Invention
Implementations described herein relate generally to devices and, more particularly, to a device that controls the illuminance of an assist light.
2. Description of Related Art
An assist light may be used in certain devices (e.g., cameras) to provide a constant light source and improve autofocus performance or exposure in low light conditions. A higher illuminance assist light typically improves the performance of the autofocus and exposure. However, at shorter distances a very bright assist light may lead to saturation of the autofocus sensor (i.e., a sensor used to control an electromechanical system of the device that adjusts the focus of the optical system), which may cause the autofocusing operation to fail. Since the speed of autoexposure is directly related to the frame rate of a camera, which in turn is related to the light level, a high illuminance assist light may be even more problematic in low light situations. A high illuminance assist light may also blind a subject (e.g., person) exposed to the assist light depending on the distance between the device and the subject.